Benefits

1. No water used, no problems of water disposal

Stimulating with propane or other light alkanes allows to save millions of m3 of used water per well, because these techniques does not require the use of a single drop of water. The non-use of water enables in particular to avoid any conflict of utilization with agriculture activities, today a concern in a number of countries, and will allow to develop shale gas in areas in the world where water is lacking.

As a consequence, the question of retreatment of high quantity of polluted water after hydraulic fracturing operations does not arise in the case of Propane or other Light Alkanes Stimulation.

The seismic risk related to the injection in the subsoil of used water is profoundly reduced as well.

2. Recovery of stimulation fluid injected

While in hydraulic fracturing, only 30-80% of water is recovered, our technologies allow a recovery of almost all injected gas (95-100%) because of the low vapor pressure of propane and other light alkanes.

The recovered stimulation gas can be sold as such (i.e. directly inserted in the pipelines) or used for subsequent stimulation operations.

In other words, Propane and other Light Alkanes Stimulation can achieve a closed loop process.

3. No chemical additives

The hydro fracturing process requires the use of a number of additives (biocides, lubricants, surfactants) sometimes considered carcinogenic substances.

The use of propane or other light alkanes in place of water, but also the research carried out by ecorpStim enables today to eliminate all chemical additives.

Only buoyant proppants (fine sand and/or carbon fullerenes) are added to the stimulation fluid.

4. A higher efficiency

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Stimulating with propane or other light alkanes is not only more elegant than hydraulic fracturing, but also helps to achieve an equal or better return.

First, because the properties of propane / other light alkanes allow recovery rates of natural gas at least equal, and probably much higher than those of water-based fracturing:

  • Propane better penetrates into the rock, due to lower surface tension and reduced viscosity, creating deeper and more even fractures.
  • Propane allows better clean-up and less clogging, reducing obstruction rates. Propane turns to a gaseous form thereby facilitating flowback while in hydraulic fracturing, large volumes of water – between 20% and 80% – and chemicals additives remain trapped in fractures.
  • Propane is recovered and re-used many times, and cost is amortized over several stimulation operations.

Using propane / other light alkanes in place of water has other benefits in terms of cost:

  • Smaller site required
  • Less equipment needed on site, smaller fluid volumes, reduction of the associated transport needs
  • Less time required to achieve stimulation (from 1/3rd to 1/10th)
  • Elimination of the costs associated with the purchase of the chemical additives, with the treatment of the stimulation fluid, the disposal of the wastewater, etc. compared with traditional hydraulic fracturing

5. Less equipment for a smaller stimulation site

The technologies developed by ecorpStim require a reduced number of equipment on site, using a reduced surface.

The elimination of water, as well as the recapture/reuse of the stimulation fluid, cuts down the number of transport trucks (conveyance and retreatment) and eliminates the need for large water storage basins/tanks.

ecorpStim’s optimized processes, consisting in successive injections of small quantities of stimulation fluids, also enable to minimize LPG storage on site.

6. Reducing the carbon footprint related to transport

The required quantities of propane / other light alkanes are significantly lower than quantity of water used for hydraulic fracturing (in particular as the gravity of liquid propane is half that of water).

The use of propane / other light alkanes reduces by 80% the carbon footprint of transportation, by avoiding the ballet of trucks that supply the thousands of gallons of water and its removal for treatment.

7. Suppression of flaring

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In the case of the re-use of the propane / other light alkanes (re-capture and compression into a liquid form again), there is a dramatic reduction (at least 90%) of surface flaring.

Furthermore, by putting methane and ethane produced during the recovery process back into the pipelines, flaring can be completely eliminated.

Thousands of tons of CO2 emissions can hereby be eliminated.

8. Security of well reinforced

A criticism raised against the hydraulic fracturing is the possibility of leakage at well level, especially during the rise of the fracturing fluid to the surface.

With Propane or other light alkanes Stimulation, a specific model of well can be used. The volume required for the passage of propane is 1/10th to 1/30th of that required for water in hydraulic fracturing. Thus an additional tubing is added, isolated with an annular space, filled with nitrogen: this enables to avoid the risks of stress (vibrations…) against the casing during the stimulation phase.

Chemical sensors and geophones are also added, to be informed in real time of any abnormality during the successive steps of the process (drilling, stimulation, production).

This extra tubing / nitrogen compartment, as well as the precautions taken by the operator, make it impossible for the gas/proppant mixture to escape.

9. Reducing seismicity risks

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The seismic risk appears more likely with higher underground injection volumes associated with wastewater disposal in depleted wells.

This issue of wastewater disposal does not arise with waterless techniques such as Pure Propane Stimulation (PPS), Light Alkanes Stimulation (LAS) and Non-Flammable Propane Stimulation (NFP).

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